Suture anchor assembly

ABSTRACT

Suture anchor assembly for attaching soft tissue to bone. The assembly (10) includes an elongated member (12) having a continuous self-tapping threaded anchor portion (14) having a self-drilling contour at its proximal end, and an integral eyelet (18) for receiving a suture (30) at its distal end. The distal end further includes a receiver for a rotating driver device (20), such as a cannulated drill. The assembly (10) is designed for endoscopic insertion of the anchor (14), with the suture (30) extending along the central axis (X 1 ) of the driver (20).

This application is a continuation of application Ser. No. 08/388,951,filed on Feb. 15, 1995, now abandoned, which is a continuation-in-partof prior application Ser. No. 08/349,677, filed on Dec. 5, 1994, nowU.S. Pat. No. 5,443,482 entitled "SUTURE ANCHOR ASSEMBLY", which is acontinuation of prior application Ser. No. 08/081,516, filed on Jun. 23,1993, now U.S. Pat. No. 5,370,662.

BACKGROUND OF THE INVENTION

The present invention generally relates to suture anchors. Specifically,the invention relates to suture anchors used in securing soft tissue tobone.

Soft tissues, such as tendons and ligaments generally insert into bonethrough small collagenous fibers called sharpey's fibers. Theseconnections are strong and permit the muscle which pull on the tendonsto effect force on the bones, or the ligaments which stabilize thebody's joints, the resist force. When a tissue is torn away from thebone and requires repair, the surgeon is often required to fashiontunnels into the bone through which to pass sutures, which are thenthreaded through the soft tissues. The bone tunnels are often difficultto make, and generally require large open incisions. Recently, throughthe advent of endoscopic surgery, where the surgeon looks into a jointcavity with a telescope, there has been a desire to repair soft tissuesback to bone without performing a large open incision. The devicedescribed herein facilitates that procedure.

A variety of devices are available for attaching objects to bone, suchas screws, staples, cement, and sutures alone. These devices have beenused to attach soft tissue, such as ligaments, tendons, muscles as wellas objects such as prostheses, to bone. Screws tend to loosen with time,usually requires a second operation to remove the loosened screw. Inaddition, conventional screws tend to be time-consuming and difficult toinstall, especially in a tight space such as that encountered duringendoscopic surgery.

Installation of presently available bone screws involves several steps.First, a pilot hole must normally be drilled into the bone. Then,depending on the bone structure, the bone may also have to be tapped toaccept to the screw. The screw is next positioned and turned to fasten.Finally, if the suture is not preattached, the suture is threaded intoan eyelet contained in the screw. This multi-step process, necessitatedby the structure of available bone screw devices, is difficult for thesurgeon, especially in confined surgical areas. Often, suchaccessibility considerations limit the ability of the surgeon to securesutures at optimal locations, forcing the surgeon to select aless-than-desirable location. Furthermore, the final position of thescrew is determined once the hole has been drilled, making it difficultto relocate or position the screw in a different position.

U.S. Pat. No. 4,632,100 discloses a cylindrical suture anchor whichincludes a drill at a first end (for boring a hole in a bone) and aflight of threads on the other end, and distal from the drill, forsecuring the anchor in a hole established by the drill. Sutures are heldin the interior of the anchor by means of an annular disc that is pressfit into the interior of the anchor. This two piece assembly isdifficult to assemble and, due to the suture-holding disc, issubstantially limited in the number of sutures that can be held.Moreover, the discrete drill and thread flights are inefficient in theiroperation.

Staples are disadvantageous for some of the same reasons as standardscrews, plus there are additional set-backs for using staples forattachment. Staples have been known to crack the bone during deployment,or to accidentally transect the object being attached to the bone.

Other devices that currently exist for attaching soft tissue to boneinclude metal screws with sutures attached, shaped metal anchors throughwhich sutures can be threaded, and plastic tacks with sutures attached.Each of these devices includes a single suture affixed to the deviceprior to implantation. These devices are difficult to deployendoscopically and are limited to single sutures even though multiplesutures are often required for soft tissue repair.

Accordingly, it is an object of the invention to provide a device thatis designed for endoscopic use and that accommodates multiple suturefixation.

SUMMARY OF THE INVENTION

The present invention generally relates to suture anchor assemblies ofthe type used for securing soft tissue to bone. The inventive assemblyincludes an elongated, generally cylindrical member having an anchorportion at a first end and a suture/drive portion at a second end. Aneyelet is positioned at the second end for receiving and securing asuture. The second end also includes a coupler for coupling a cannulateddriver to the anchor to enable insertion of the anchor into bone.

The cylindrical member of the anchor assembly generally extends along acentral axis X, and has a maximum outer diameter D. The anchor portionincludes a self-drilling contour near the first end. Both the anchorportion and the suture/drive portion have a continuous self-tappingthread pattern on their outer surfaces.

The eyelet is positioned near the second end such that a suture path isdefined from the region adjacent to the second end, through the eyeletand back to the region adjacent to the second end. The endpoints of thesuture path are less than D'/2 from the central axis. In a preferredform of the invention, D' is less than the maximum outer diameter of thecylindrical member D.

The coupler that forms part of the suture/driver end of the cylindricalmember is adapted to mechanically couple a distal tip of a cannulateddriver. The driver may have an inner diameter greater than or equal tothe diameter D₁ of the suture/driver end and an outer diameter less thanor equal to diameter D. The driver is rotatable about a drive axis andthus rotates the cylindrical member about that drive axis when thedistal tip of the driver is mechanically coupled with the coupler.

In another embodiment, the coupler includes at least first and secondplanar flanges located at opposite sides of the central axis, andextending radially outward from the central axis in opposite directions.The coupler may further include third and fourth planar flanges, also onopposite sides of and extending radially outward from the central axis.The flanges function as stop-points, or form a shoulder, to prevent thecylindrical member from being inserted beyond a predetermined point intothe bone.

The coupler may also include one or more pairs of grooves in the side ofthe cylindrical member and extending from the second end to the firstend. The grooves extend along groove axes essentially parallel to thecentral axis. Each groove of each pair of grooves is located on oppositesides of the cylindrical member, and the respective opposing groove axesare essentially coplanar with the central axis.

In another embodiment the suture anchor assembly of the presentinvention further includes a cannulated driver with a distal tip havingan inner diameter D₂ which is greater than or equal to D'. Thecannulated driver can include an annular tapered leading edge.

In another embodiment, the anchor portion includes a self-drillingcontour at least at points near the first end.

In yet another embodiment, the anchor portion and the suture/driveportion have a continuous self-tapping thread pattern on their outersurfaces. The thread pattern extends at least from points near the firstend to points near the second end.

The anchor portion can include drilling means at its distal tip forestablishing a hole in bone. The suture/drive portion includes an eyeletwhich is bounded by a pair of channels extending axially therein fromthe second end of the cylindrical member. The channels are on oppositesides of the suture/drive portion and are linked by a central aperture.The channels can be either external or internal.

BRIEF DESCRIPTION OF THE FIGURES

The invention is further described by the following description, andFigures in which:

FIG. 1 shows a side plan view of one embodiment of the suture anchorassembly of the present invention;

FIG. 2 shows an alternate side plan view of the embodiment of FIG. 1rotated 90° from FIG. 1;

FIG. 3 shows a longitudinal cross-section view of a driver assemblyengaging the suture anchor assembly of FIG. 1;

FIG. 4 shows a perspective view of another embodiment of the inventivesuture anchor assembly, including the distal portion of a driverassembly,

FIG. 5 shows a perspective view of another embodiment of the inventivesuture anchor assembly, including the distal portion of a driverassembly;

FIG. 6 shows a perspective view of another embodiment of the inventivesuture anchor assembly, including the distal portion of a driverassembly;

FIG. 6A shows an end view of the suture anchor assembly of FIG. 6;

FIG. 7 shows a perspective view of another embodiment of the sutureanchor assembly of the present invention, including the distal portionof a driver assembly;

FIG. 7A shows an end view of the suture anchor assembly of FIG. 7;

FIG. 8A shows a side plan view of another embodiment of the inventivesuture anchor assembly;

FIG. 8B shows an end view of the suture anchor assembly of FIG. 8A fromthe drive end;

FIG. 8C shows a longitudinal cross-section of the suture anchor assemblyof FIG. 8A;

FIG. 8D shows an end view of the suture anchor assembly of FIG. 8A fromthe anchor end;

FIG. 8E shows a cross-section of the anchor of FIG. 8A together with adrive assembly;

FIG. 8F shows an exploded perspective view of the driver of FIG. 8E;

FIG. 9A shows a side plan view of another embodiment of the inventivesuture anchor assembly;

FIG. 9B shows a cross-section of the suture anchor assembly of FIG. 9A;

FIG. 9C shows a perspective view of a driver for use with the anchor ofFIGS. 9A and 9B;

FIG. 9D shows a sectional view of the driver of FIG. 9C;

FIG. 10A shows a side plan view of another embodiment of the inventivesuture anchor assembly;

FIG. 10B shows a cross-section of the suture anchor assembly of FIG.10A;

FIG. 11A is an end view of another embodiment of the inventive sutureanchor assembly;

FIG. 11B is a side elevational view of the embodiment of FIG. 11A;

FIG. 11C is a partial longitudinal cross-sectional view of theembodiment of FIG. 11B;

FIG. 12A is an end view of still another embodiment of the inventivesuture anchor assembly;

FIG. 12B is a side elevational view of the embodiment of FIG. 12A;

FIG. 12C is a partial longitudinal cross-sectional view of theembodiment of FIG. 12B;

FIG. 13A is an end view of a driver for use with the suture anchorassembly of FIG. 11B;

FIG. 13B is a longitudinal cross-sectional view of the driver of FIG.13A;

FIG. 14A is an end view of a driver for use with the suture anchorassembly of FIG. 12B;

FIG. 14B is a longitudinal cross-sectional view of the driver of FIG.14A;

FIG. 15A is an end view of another embodiment of the inventive sutureanchor assembly;

FIG. 15B is a side elevational view of the suture anchor assembly ofFIG. 15A;

FIG. 15C is an end view of a dirver for use with the suture anchorassembly of FIGS. 15A-15B;

FIG. 16A is an end view of still another embodiment of the inventivesuture anchor assembly;

FIG. 16B is an end view of a driver for use with the suture anchorassembly of FIG. 16A; and

FIG. 17 is a side elevational view of a suture anchor having aself-tapping thread pattern extending along its full length.

Like elements in the respective FIGURES have similar reference numbers.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The suture anchor assembly of the present invention primarily is for useduring endoscopic surgery. The anchors are intended for permanentimplantation into a patient, however it is possible to remove theanchors if necessary. The use of suture anchors that fix soft tissue tobone is frequent in orthopedic surgery, though such anchors may be usedin other fields as appropriate.

Generally, and as illustrated in FIGS. 1 and 2, the inventive sutureanchor assembly 10 includes an elongated cylindrical member 12. Thecylindrical member 12 includes a threaded anchor portion 14 at one endand a suture/drive portion 16 at the opposite end. The suture/driveportion 16 is adapted for insertion into the distal end of a driver 20,such as a standard operating room cannulated drill. The inventiveassembly 10 is thus adapted for installation into a patient byendoscopic means, or any other appropriate surgical procedure. Theinventive assembly 10 may include several different embodimentsillustrated and described herein.

Preferably, the cylindrical member 12 is manufactured from stainlesssteel, titanium, or some other durable, non-degradable, biocompatiblematerial. Alternatively, the cylindrical member 12 may be manufacturedfrom a non-biocompatible material, but coated with a biocompatiblesubstance prior to insertion in the patient. The assembly 10 may bemanufactured as a single piece, using standard metal-shaping techniques.Alternatively, the top portion 16 may be manufactured separately fromthe bottom anchor portion 14 and attached by conventional methods andmaterials. In such an embodiment, the two separate portions may bemanufactured using the same or different materials.

In one form, the anchor portion 14 may be metal, forming a permanentelement, while the suture/drive portion 16 may be made of abioresorbable material (which will be resorbed after residing in apatient). The latter form is particularly useful where it is theeventual goal to have no protuberance beyond the bone surface.

The threaded anchor portion 14 of the cylindrical member 12 covers aportion of the surface of that member 12. The actual amount of threadedanchor portion 14 may depend upon several variables, such as the type oftissue, the type of anticipated surgical procedure in which the assemblywill be used, manufacturing limitations, materials limitations, andother variables readily determinable by one skilled in the relevant art.

The top suture/driver portion 16 at the distal end of the assembly 10 isdesigned both to hold a suture material and to fit the head of a driverdevice. In the illustrated embodiment of FIG. 1, the top portion 16includes an eyelet 18 of sufficient size to receive one or more sutures30. Since sutures are made of different materials and, consequently, areavailable in a variety of different diameters, the actual size of theeyelet 18 may be of a standard size to accept any suture material or maycome in a range of sizes specific to different suture types.

In alternative embodiments, and as exemplified in FIG. 5, the topportion 16 may includes a plurality of aligned eyelets 18 to enable oneor more sutures to pass through two or more such eyelets 18.Alternatively, multiple sutures may pass through any one of the eyelets.The suture 30 is preferably prethreaded in the suture anchor 10, but maybe threaded once the anchor assembly 10 is positioned. Generally, thesuture 30 passes through a suture path P through eyelet 18. Theoutermost boundary of suture path P is less than distance D'/2 from thecentral (X) axis of anchor 10, i.e. within the cylindrical regionaldiameter (D, where D'≦D) defined by the greatest diameter of thecylindrical member 12. This restriction on the diameter of path P isnecessitated by the requirement that the top portion 16 (and suture 30)fit into a distal tip 22 of a cannulated driver assembly 20, as shown inFIG. 3.

FIG. 3 illustrates the driver assembly 20 interfitted with the anchorassembly 10 of FIGS. 1 and 2. As shown, the driver assembly 20 includesa distal tip element 22 that extends from a cannulated member 23. Thedistal tip element 22 interfits with suture/drive portion 16. The outerdiameter D₃ of the distal tip 22 preferably is less than or equal toouter diameter D of the cylindrical member. This reduces the amount oftrauma to surrounding tissue during insertion of the assembly 10.

As shown in the Figures, the anchor portion 14 of the cylindrical member12 is preferably self-tapping. The tip of the anchor portion 14 maytaper to a point, or may be blunt-ended depending upon the specificenvironment in which the suture anchor assembly 10 will be used. Othertapered configurations may be used. In a preferred embodiment, and asillustrated, the tip is pointed to facilitate inserting the anchorassembly 10 at an optimal location selected by the user.

The outermost diameter D, as measured at the widest portion of thecylindrical member 12, may vary depending upon such variables as thespecific environment for which the assembly 10 will be used, thematerials from which the assembly 10 is manufactured, and othervariables readily determined by one skilled in the relevant art. In apreferred form of the invention, the cylindrical member 12 of a typicalassembly may have D approximately equal to 0.2 inches.

The top portion of the cylindrical member adjacent to the top portionmay include a shoulder 17 that extends beyond the diameter D of thecylindrical member 12, as shown in FIG. 1. Thus, the shoulder 17 mayconsist of a set of discrete shoulder flanges, or may be a continuousportion of the top of the cylindrical member that extends beyonddiameter D. The shoulder 17, whether in the form of discrete flanges ora continuous extension portion, functions to stop insertion of theanchor assembly 10 into the bone beyond the shoulder 17. Thus, theshoulder 17 prevents a user from inserting the assembly 10 so far intothe bone that the suture/driver portion 16 becomes lodged in the bone.

In a preferred form of practicing the present invention, thesuture/drive portion 16 is adapted to fit into the chuck of a standardoperating room cannulated drill generally commercially available. Inother forms of practicing the invention, a driver assembly 20 may beused having a distal tip element 22 adapted to interfit with thesuture/drive portion 16 of the inventive assembly. In a preferred formof the invention, and as best shown below in conjunction with FIG. 4,the inner diameter D₂ of the driver tip 22 is greater than or equal tothe diameter D₁ of suture/drive portion 16.

The distal tip 22 is cannulated to allow the suture/drive portion 16,with sutures in place in the suture path, to extend into the distal tipelement 22. In one embodiment, the drive assembly 20 is cannulated,however it may only be necessary for the tip 22 to be cannulated anamount sufficient to receive the suture/drive portion 16, with sutures.

In a preferred form of practicing the present invention, the driverassembly 20 is rotatable about an axis X₁, which axis X₁ is coaxial witha central axis X₂ along which the cylindrical member 12 extends. Thus,when the anchor assembly 10 is engaged with the drive assembly 20, thedrive assembly 20 rotates the anchor assembly 10 in such a manner as toscrew the anchor 10 into the target bone.

In the illustrated embodiment of FIG. 4, the suture/drive portion 16consists of a pair of planar flanges 24, 24' extending radially outwardfrom and on either side of the central axis X₂. A suture eyelet 18extends through the flanges 24, 24'. The distal tip element 22 of driver20 has an inner geometry that is complementary to the outer geometry offlanges 24, 24', so that the distal tip element can engage the flangesfor rotational driving.

In an alternative embodiment shown in FIG. 5, the suture/drive portion16 includes four planar flanges, 24a, 24b, 24c, and 24d, each flangepositioned about 90° from the other about the central axis. Thegenerally "+"-shaped cross-section formed by the planar flanges theninserts into a complementary pattern in the driver distal tip element22.

In yet another embodiment, shown at FIG. 6, the cylindrical member 12includes a pair of grooves 26, 26' extending from the suture/driveportion end of the member 12. The grooves 26 may extend either theentire length of the cylindrical member 12, or, as shown in FIG. 6, mayextend only a portion of the way down the member 12. The exact lengthand depth of each groove depends on such variables and considerations asmanufacturing constraints, the type of driver used, and other variablesreadily discernible by one skilled in the relevant art. For this form ofthe invention, the distal tip element 22 of driver 20 includes a pair ofridges 27, 27' that are complementary to grooves 26, 26', so that thedriver 20 can engage the end of member 12.

As shown in the top plan view of this embodiment of the assembly 10 inFIG. 6A, a structure 28 may be provided solely for the suture eyelet 18.As illustrated, the eyelet structure 28 has a length L less than orequal to the diameter D of the cylindrical member. The structure 28 ispositioned at the end of the cylindrical member 12 opposite the anchorportion 14. The structure may be integral to the cylindrical member 12or may be mechanically or otherwise attached to the cylindrical member12.

In another alternative embodiment, and as illustrated in FIG. 7, theinventive assembly 10 may include a plurality of grooves 26a, 26b, 26c,and 26d positioned in predetermined locations about the surface of thecylindrical member 12. These grooves 26a, 26b, 26c, and 26d, arestructurally similar to the grooves 26 and 26' described in relation toFIG. 6. As further illustrated in FIG. 7A, this illustrated embodimentincludes a suture structure 28 having characteristics to the similarstructure 28 described above in conjunction with FIGS. 6 and 6A. Thedistal tip element 22 of driver 20 for the anchor of FIGS. 7 and 7Aincludes four internal ridges 27a, 27b, 27c, and 27d.

Yet another embodiment of the anchor 10 is shown in FIGS. 8A, 8B, 8C and8D. That anchor is generally similar to that of FIG. 5, except that themember 12 includes a square cross-section central bore 40 extendingalong its central axis X₂, having dimensions d/√2×d/√2. In this element,a flanges 50, 52, 54 and 56 each include a respective one of sutureeyelets 50a, 52a, 54a and 56a, and determine suture paths positionedsuch that all points are separated from the central axis X₂ by adistance greater than d/2.

The anchors of FIGS. 8A-8D are particularly adapted for driving with asquare cross-section driver positioned in the central bore 40. FIGS. 8Eand 8F show a cannulated driver 20 having a tip 22 which supports adrive element 60 extending from an aperture 64 in tip 22. The driveelement 60 includes a square cross-section portion 70 (for drivinganchor 10) and a cylindrical lead portion 72 (for guiding the lead tipof anchor 10 into a pilot hole in the target bore). In thisconfiguration, the tip 22 also includes apertures 76 and 78 to define asuture path between the eyelets of anchor 10 and the interior ofcannulated driver 20.

FIGS. 9A and 9B and FIGS. 10A and 10B show additional embodiments of theinvention. The anchors of these figures include shoulders 17, whichserve to limit the insertion depth of the anchors. Also theseembodiments include different exemplary suture eyelet configurationcompared with the configurations of the other figures.

The embodiment of FIGS. 9A and 9B is particularly adapted for use withthe driver 80 shown in FIGS. 9C and 9D. That driver 80 includes anelongated tubular member extending along a driver axis 82 between aproximal end 80a and a distal (or driving) end 80b. A pair of resilient,elongated finger members 84 and 86 extend from the distal end alongrespective finger axes 84a and 86a, respectively; axes 84a and 86a aresubstantially coplanar with axis 82. The finger members 84, 86 areshaped so that the anchor 10 of FIGS. 9A and 9B may be supported by thefinger members 84, 86, with those finger members fitting within theelongate grooves 26 and 26' in the outside of member 14. The separationS1 of fingers is such that upon placement an anchor 10 between fingermembers 84, 86 in alignment with grooves 26, 26', the separation S1between finger members is slightly increased, and the resilient fingerseffect a bias force, holding the anchor 10 in place. Thus, the fingers84, 86 act as spring-biased flexures to support an anchor. Preferablythe driver 80 has a pair of slots 90, 92 in its distal top, as shown,which are adapted to receive element 16 upon full insertion of fingermembers 84, 86 into grooves 26, 26'. With this configuration, acontrolled, substantial driving torque may be applied to the drive endof the anchor 10 for insertion.

One aspect of the present invention, and as shown in the figures, isthat the anchor portion 14 may include a self-tapping threaded portion.The self-tapping aspect of the threaded anchor portion facilitatesinsertion of the anchor assembly 10 into a patient's bone or otheranchor base at a location desired by the practitioner. Unlike prior artdevices that require the creation of an initial insertion hole beforeintroduction of a screw-type anchor, the self-tapping aspect of thethreaded portion of the inventive suture anchor assembly allows the userto select the optimal location for insertion of the assembly 10.

According to another embodiment of the present invention, the anchorportion 14 can have a self-drilling contour at least at points near thefirst end of the cylindrical member 12, as shown in FIGS. 11B and 12B.The self-drilling contour can include a self-drilling bit at the distalend of the anchor portion 14 for establishing a hole in cancellousand/or cortical bone.

The anchor portion 14 and the suture/drive portion 16 have a continuousself-tapping thread pattern which extends over the outside surface ofsubstantially the entire length of the respective portions, as shown inFIGS. 11B and 12B. The self-tapping thread pattern can extend from thefirst end to the second end, or from points near the first end to thesecond end, or from the first end to points near the second end as shownin FIG. 17. The self-tapping thread pattern can extend to the outersurface of at least a portion of the self-drilling bit at the distal endof the anchor portion.

The suture anchor 10 can thus be a fully threaded shaft with no head atthe suture/drive end 16 as shown in FIG. 17. Alternatively, the sutureanchor can include, for example, a pan head or other flat head formedwith shoulder 17, as illustrated in FIGS. 11B, 11C, 12B AND 12C.

The suture/drive portion 16 includes one or more eyelets 18 positionedat or near the second end. In a preferred embodiment, the eyelet 18 isfully recessed within the elongated cylindrical member, as shown inFIGS. 11B and 11C. As shown in FIGS. 11A-11C, channels 19 are linked byeyelet aperture 18 within the suture/drive portion 16 to define a suturepath P. The diameter D' of the suture path P is less than the maximumouter diameter D of the cylindrical member 12, as shown in FIG. 11C.Sutures 30 pass through the channels 19 and eyelet aperture 18 along thesuture path P. The channels 19 can be externally located on the outersurfaces of the cylindrical member 12, as shown in FIGS. 11A-C, or theycan be internally located within the cylindrical member 12, as shown inFIGS. 12A-12C. The eyelet aperture 18 can be drilled completely throughthe suture/drive portion 16 at the second end of the suture anchorassembly 10, as shown most clearly in FIG. 12C.

The suture/drive portion 16 includes coupling means for receiving adistal tip 22 of a cannulated driver 20, so that the cylindrical member12 of the suture anchor assembly and the driver tip 22 can bemechanically coupled for mutual rotation.

FIGS. 13A and 13B show a cannulated driver 20 which can be used with thesuture anchor assembly of FIGS. 11A-11C. The suture anchor embodiment ofFIGS. 11A-11C features external channels 19 on the outside surfaces ofthe suture/drive portion 16. The distal tip elements 22 of thecannulated driver 20 have an inner diameter D₂ which is greater than orequal to the diameter D' of the suture path P, and an outer diameter D₃which is less than or equal to the maximum outer diameter D of thecylindrical member 12 of the suture anchor. The distal tip elements 22are adapted to interfit with the channels 19, and to abut surfaces 21 ofthe suture/drive portion 16, for imparting axial and rotational force tothe suture anchor. The distal tip elements 22 of the driver 20 areconfigured to define a suture path P between them, as shown in FIGS. 11Cand 13A.

FIGS. 14A and 14B show a cannulated driver 20 which can be used with thesuture anchor assembly of FIGS. 12A-12C. The suture anchor embodiment ofFIGS. 12A-12C features internal channels 19 within the suture/driveportion 16. Note that, relative to the driver 20 of FIG. 13A, the distaltip elements 22 of this driver embodiment are more closely spaced anddefine a narrower suture path P' between them, as illustrated in FIGS.12C and 14A. Smaller-gauge sutures 30' must be used with the sutureanchor embodiment of FIGS. 12A-12C and the driver embodiment of FIGS.14A-14B because of the narrower suture path P' and the closer spacing ofthe channels 19 and the distal tip elements 22 of the driver 20.

The driver 20 further includes an annular tapered leading edge portion31, as shown in FIGS. 13A-13B and 14A-14B. This tapered leading edge 31permits the driver 20 to set the suture anchor 10 slightly (e.g., 1-2mm) below the top surface of the cortical bone. When the driver 20 isdisengaged from the suture anchor 10 after the anchor is installed inthe bone, one or more sutures 30 which remain with the suture anchor 10contact a gradually tapered edge of bone at the point of entry of theanchor 10 into the bone. This elimination of sharp bone surfacesprotects the sutures 20 from premature fraying and also reduces stresson the bone itself.

FIGS. 15A-15B illustrate another suture anchor embodiment in which fourexternal channels 19 are provided in the suture/drive portion. Each ofthe channels 19 is narrower relative to the channels in the embodimentof FIGS. 11A-11C. A driver 20 for use with this embodiment isillustrated in FIG. 15C. A three-channel embodiment of a suture anchor10 and corresponding driver 20 is illustrated in FIGS. 16A-16B. Othersuture anchor and driver embodiments employing different numbers andarrangements of channels 19 are possible.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments and examples are therefore to be considered in all respectsas illustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes that come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed is:
 1. A surgical suture anchor assembly, comprising:anelongated, generally cylindrical member extending along a central axisand having a maximum outer diameter D, said member including an anchorportion at a first end thereof rigidly coupled to a suture/drive portionat a second end thereof, said second end being opposite said first end,wherein said anchor portion includes a self-drilling contour at least atpoints near said first end, andwherein said suture/drive portionincludes: A. at least one eyelet positioned at or near said second end,said eyelet having a central aperture, whereby a suture path extendingbetween two end points is defined by a region adjacent to said secondend, through said aperture of said eyelet and back to said regionadjacent to said second end, wherein the end points of said suture pathare less than a distance equal to D'/2 from said central axis, where D'is less than or equal to said maximum outer diameter D; and B. couplingmeans for receiving a distal tip of a cannulated driver rotatable abouta drive axis, whereby said cylindrical member and said distal tip aremechanically coupled for mutual rotation with said drive axis and saidcentral axis being coaxial when said distal tip of said driver isreceived by said coupling means, and wherein said anchor portion andsaid suture/drive portion have a continuous self-tapping thread patternon the outer surfaces thereof, said pattern extending at least frompoints near said first end to points near said second end.
 2. A sutureanchor assembly according to claim 1 further including a cannulateddriver wherein said distal tip of said driver has an inner diameter D₂greater than or equal to D'.
 3. A suture anchor assembly according toclaim 2 wherein said cannulated driver includes an annular taperedleading edge.
 4. A suture anchor assembly according to claim 1 whereinsaid distal tip of said driver has an outer diameter D₃ less than orequal to D.
 5. A suture anchor assembly according to claim 1 furthercomprising a plurality of sutures extending along said suture path.
 6. Asuture anchor assembly according to claim 1 wherein said anchor portionhas drilling means at a distal tip thereof for establishing a hole inbone.
 7. A suture anchor assembly according to claim 1 wherein saideyelet is bounded by a pair of channels extending axially within saidsuture/drive portion from said second end, said channels being ondiametrically opposite sides of said suture/drive portion and beinglinked by said central aperture.
 8. A suture anchor assembly accordingto claim 1 wherein said thread pattern extends from said first end tosaid second end of said member.
 9. A suture anchor assembly according toclaim 1 wherein said thread pattern extends from points near said firstend to said second end of said member.
 10. A suture anchor assemblyaccording to claim 1 wherein said thread pattern extends from said firstend to points near said second end of said member.
 11. A suture anchorassembly according to claim 1 wherein said thread pattern extends to theouter surface of at least a portion of said drill means at said distaltip of said anchor portion.
 12. A suture anchor assembly according toclaim 7 wherein said channels within said suture/drive portion areinternal.
 13. A suture anchor assembly according to claim 7 wherein saidchannels within said suture/drive portion are external.
 14. A driverassembly for releasably supporting a suture anchor assembly wherein saiddriver assembly comprises:A. an elongated tubular member extending alonga driver axis and having a proximal end and a distal end, and B. a pairof resilient, elongated finger members extending from opposite sides ofthe end of said distal end of said tubular member and along respectivefinger axes parallel to said driver axis, said finger axes and saiddriver axes being substantially coplanar, wherein said finger membersare separated by a first distance S1 at said distal end of said tubularmember and by lesser distances at other locations along said driveraxis, and wherein said finger members are adapted to interfit with saidchannels to define said suture path.
 15. A surgical anchor kit,comprising:I. an elongated, generally cylindrical member extending alonga central axis and having a maximum outer diameter D, said memberincluding an anchor portion at a first end thereof rigidly coupled to asuture/drive portion at a second end thereof, said second end beingopposite said first end,wherein said anchor portion includes aself-drilling contour at least at points near said first end, whereinsaid suture/drive portion includes:A. at least one eyelet positioned ator near said second end, said eyelet having a central aperture, wherebya suture path extending between two end points is defined by a regionadjacent to said second end, through said aperture of said eyelet andback to said region adjacent to said second end, wherein the end pointsof said suture path are less than a distance equal to D'/2 from saidcentral axis, where D' is less than or equal to said maximum outerdiameter D; and B. coupling means for receiving a distal tip of acannulated driver rotatable about a drive axis, whereby said cylindricalmember and said distal tip are mechanically coupled for mutual rotationwith said drive axis and said central axis being coaxial when saiddistal tip of said driver is received by said coupling means, andwherein said anchor portion and said suture/drive portion have acontinuous self-tapping thread pattern on the outer surfaces thereof,said pattern extending at least from points near said first end topoints near said second end, II. a driver assembly for releasablysupporting a suture anchor assembly wherein said driver assemblycomprises:A. an elongated tubular member extending along a driver axisand having a proximal end and a distal end, and B. a pair of resilient,elongated finger members extending from opposite sides of the end ofsaid distal end of said tubular member and along respective finger axesparallel to said driver axis, said finger axes and said driver axesbeing substantially coplanar, wherein said finger members are separatedby a first distance S1 at said distal end of said tubular member and bylesser distances at other locations along said driver axis, and whereinsaid finger members are adapted to interfit with said channels to definesaid suture path.